Bitmain Antminer S21+ (235Th) firmware

Official firmware versions matched to the exact ASIC model or manufacturer family. Local copies include SHA-256 checksums.

Firmware is hardware-specific. Match the exact model and control-board revision, back up settings, use stable power, test one miner first, and never interrupt an upgrade. A wrong image can make the controller unbootable.

Official manufacturer firmware

1 versions

Exact model Official source: BITMAIN Product Manual & Firmware ↗

Version	Published / updated	Compatibility	Size	SHA-256	Download
FR-1.40FR-1.40(260721-S21+).bmu	2026-08-31	ANTMINER S21+	16.3 MB	`—`MD5: 0cd7364656229372177d789974f16791	Official listing; local copy unavailableOfficial source ↗
Release notes: MD5:0cd7364656229372177d789974f16791 Updates： 1. Optimized firmware. Please make sure the miner type and firmware type are the same before upgrading the miner firmware.

Verify the downloaded file with SHA-256 before uploading it to a miner.

Sources checked 14 September 2026